Materials capable of absorbing liquids, particularly aqueous liquids, are employed in numerous everyday uses, such as in the manufacture of towels (cloth or paper) and various specialty absorbing materials, such as diapers and other absorbent garments, wound dressings, medical sponges, tissues, napkins, liners, toilet paper, tampons, sanitary napkins, towelettes, and cleaning wipes. Other commonly used absorbents include aerosol absorbents such as antiperspirants, and bulk liquid absorbents, which are often in the form of powders and are frequently used to absorb large spills on surfaces. These materials have traditionally been prepared from cloth or paper, but recent developments have resulted in a number of absorbent material of different structure, such as hydrogels and hydroxymethylmethacrlyate. See, for example, U.S. Pat. Nos. 4,935,022; and 4,685,909. Absorbent materials have previously been prepared from cellulosic fibers, blown microfibers, staple fibers, ion exchange fibers, and conjugate fibers of different melting points. See for example, U.S. Pat. Nos. 4,851,284; 4,818,598; and 4,865,596. In addition, web structures prepared from entangled hydrophilic nylon microfibers which contain staple fibers and/or particles of hydrogel-forming polymeric gelling agent are described in U.S. Pat. No. 4,923,454. There exists a continual need to provide optimum functional properties of absorbency at moderate costs.
Bioelastic polypeptides are a relatively new development that arose in the laboratories of the present inventor and which are disclosed in a series of previously filed patents and patent applications. For example, U.S. Pat. No. 4,474,851 describes a number of tetrapeptide and pentapeptide repeating units that can be used to form a bioelastic polymer. Specific bioelastic polymers are also described in U.S. Pat. Nos. 4,132,746; 4,187,852; 4,500,700; 4,589,882; and 4,870,055. Bioelastic polymers are also disclosed in related patents directed to polymers containing peptide repeating units that are prepared for other purposes but which can also contain bioelastic segments in the final polymer; see U.S. Pat. No. 4,605,413. A number of other bioelastic materials and methods for their use are described in issued U.S. patents and pending U.S. patent applications including the following: "Stimulation of Chemotaxis by Chemotactic Peptides," U.S. Ser. No. 355,090, filed May 16, 1989, now abandoned ; "Bioelastomer Containing Tetra/Pentapeptide Units," U.S. Pat. No. 4,898,926, filed Jun. 15, 1987; "Reversible Mechanochemical Engines Comprised of Bioelastomers," U.S. Pat. No. 5,032,271, filed Sept. 20, 1989; "Bioelastomeric Materials Suitable for the Protection of Wound Repair Sites," U.S. Pat. No. 5,250,516, filed Apr. 21, 1988; "Elastomeric Polypeptides as Vascular Prosthetic Materials," U.S. Ser. No. 184,873, filed Apr. 22, 1988; and "Polynonapeptide Bioelastomers having an Increased Elastic Modulus," U.S. Pat. No. 5,064,430, filed Feb. 23, 1989. All of these patents and patent applications are herein incorporated by reference, as they describe in detail bioelastomers that can be used in the compositions and methods of the present invention. These bioelastic materials have been proposed for a number of uses, as indicated by the general subject matter of the applications and patents as set forth above.
The present invention is directed to a new use of bioelastic materials, namely as an absorbent, either alone or in combination with previously known absorbents and structural materials. It has been discovered that bioelastic materials have a number of properties, including but not limited to controllable absorbency, that make them ideal for use in a number of situations that require high levels of absorbency.